Problem description

This is an improvement on #903 (external process execution instrumentation).

Starting from Java 9, there is a new API available for process execution ProcessHandle, which is not covered by #903.
As a result, any usage of this API will not result in spans be created.

Proposed solution

Instrument Process.toHandle() to wrap returned ProcessHandle instance.

Wrapped ProcessHandle should end current process span on those methods

• ProcessHandle.destroy()
• ProcessHandle.destroyForcibly()
• ProcessHandle.onExit() > returns a CompletableFuture which should be wrapped and terminate span

This would also allow to use ProcessHandle.Info and capture program arguments, PID or other attributes.

Alternatively, we could also use CompletableFuture.thenApply(...) to chain a task that will terminate the process span.